Liquified petroleum gas (LPG) is generally utilized as a fuel or liquid which vaporizes at ambient pressures and temperatures, but which is stored in containers under pressure in liquid form. Most conventional burning appliances which utilize LPG are relatively simple, comprising a valve adapted to connect the pressurized LPG container to a burner. Most of these burning appliances operate on a vapor-withdrawal principle, drawing vapor from the container. The container is generally oriented so that the liquid settles to the bottom and the self-pressurized vapor collects at the top. The appliance draws this vapor from the container in order to fuel the burner.
While simple to operate, this type of burning appliance has several drawbacks. As the vapor is withdrawn, the pressure in the container will drop. Also, additional vapor will bubble from the remaining liquid in the container. As this occurs, the liquid will cool and the pressure in the container will drop further. As the pressure drops, so does the output of the burning appliance. In addition, if the fuel is a mixture of gases, such as a commonly used blend of propane and butane, these different components will bubble out of the liquid at different rates. Thus, the mixture of the gaseous components in the vapor will change, altering the performance of the appliance as it consumes the fuel. All of these factors, which are aggravated at low temperatures, result in inconsistent burner output.
Prior attempts to develop burning appliances, which operate on liquid-withdrawal principles generally involve a porous wick depending from a check valve within the container. The wick draws liquid fuel from the container, and the fuel is vaporized after it is extracted from the container. While these liquid withdrawal arrangements do not suffer from cold weather performance difficulties to the same extent as vapor withdrawal appliances, it is difficult to maintain a sufficient wicking rate to keep up with the output demands of many appliances, particularly at low fuel levels.
Thus, there is a need in the art for a pressurized LPG container which permits withdrawal of liquid fuel from the container, and from which liquid fuel can be withdrawn at an acceptable rate, regardless of fuel levels.
In order to withdraw liquid from a canister of a container using a dip tube, it is necessary that the dip tube be submersed in the liquid in the canister. This can be accomplished by orienting the canister. For example, the dip tube can be straight, and the canister can be designed to operated in the upright position. Alternatively, the dip tube can be designed to extend to a sidewall of the canister, and the canister can be designed to be oriented with the dip tube pointing down, to where the liquid will accumulate. However, these approaches require the canister orientation to be maintained, which can be burdensome in a camping setting.
Thus, there is a need in the art for a canister from which liquid can be withdrawn regardless of the canister orientation.
With liquid withdrawal, it is desired that the liquid fuel be properly vaporized before it reaches the burner. Thus, there is an additional need in the art for a connector between the fuel container and the burning appliance which assists in vaporizing the fuel.
Because campers and backpackers seek to minimize the volume, weight, and amount of equipment they carry, appliances such as camp stoves must be compact, lightweight, and versatile, yet easy to assemble and operate. It is therefore desirable to provide a compact, lightweight, and versatile portable stove.
U.S. Pat. No. 4,177,790 to Zenzaburo, for a "Pocket Camp Stove", discusses one such approach, in which a stove has three wire legs attached to a hub. The three legs are movable between a folded position, in which all three legs are relatively together, and an in-use position, in which the three legs are substantially equally spaced apart and extend radially outwardly from the hub member. Although this stove is compact and lightweight, the independently movable legs can be awkward to manipulate and unstable if not properly oriented.
Thus, there is a need in the art for a stove frame which not only is compact, lightweight, and versatile but which also is stable and simple to operate.
It is often challenging to achieve a proper fuel flow to a burning appliance during start-up. Often, the flow rates will be set too high or low for proper ignition. It is difficult to gauge from sight or sound exactly how far a valve should be opened prior to ignition. Therefore, it is desirable to provide a mechanism by which the fuel flow rate can be properly controlled during start-up.
It is also desirable to provide a quick and simple mechanism for securing a container to a burning appliance. One attempt, Iwaniti's CB-55E stove, connects the canister by providing a notch in an extended rim of the canister cap. This notch matches a lever on the stove adjacent the valve mechanism. In order to engage the canister to the stove, the canister has to be oriented so that the lever fits within the notch. Once engaged, turning the canister actuates the lever, which, in turn, actuates a revolving collet. Within the collet sits a stationary cam. As the collet revolves, it contacts the cam, which forces fingers of the collet into a groove in the canister cap, securing the canister to the stove.
While such a mechanism provides a secure connection between the canister and the stove, it requires the canister to be oriented properly for engagement. It also requires that the canister include an extended canister rim, which increases the overall size of the canister.
Thus, there is a need in the art for a connector which permits a simple mechanism for securing a canister to a burning appliance or other outlet, and which does not require considerable effort to orient prior to connection, and which does not increase the overall size of the canister.